I agree with Tim that Mr Farage's suggestion of Conservative/UKIP candidates at the next election is a tease – or, perhaps, a clever piece of psych-ops designed to divide and confuse Tory activists, and set them chattering.

The UKIP leader is suggesting that local Tory Associations detach themselves from their party nationally and give a different party a big say locally in candidate choice. He knows well that this will only happen very rarely, if at all.

But having asked around and spoken to senior UKIP sources, I think that his real game is a variation on this theme. Let's examine how UKIP could make a major strategic breakthrough in British politics, given that –

First-past-the-post doesn't exactly help smaller parties, such as UKIP.

The party has no winning record in by-elections and to date has been not much kop at them (though it did come second in Barnsley).

Success in Euro-elections hasn't been followed by success at general elections – and there's no reason why this should change in 2014, even if the party comes top of the poll.

I think the answer lies in the gathering prospect of an In/Out referendum – which the Labour Party is toying with and the People's Pledge is enthusiastically campaigning for. Such a referendum would deliver what Mr Farage was feinting at in his offer of joint candidates.

Namely, a Conservative split: in such a referendum, a big proportion of the party would vote No while the leadership (it must be assumed) would vote yes. A recent ComRes poll found that 51% of Tory supporters would vote to leave. My guess is that activists' views are similar.

The only referendum on Europe that has taken place in Britain had vast medium-term political consequences. The divisions in Labour which it exposed took radical form in scarcely more than five years – when part of Labour's pro-EU wing broke away to form the SDP.

Mr Farage surely envisages a similar process in the event of an In-Out referendum, whereby the centre-right of the Conservative Party and UKIP are eventually welded together to form a new right-wing force. A scenario by which an In-Out poll could be delivered is as follows:

UKIP continues to try to build up its credentials as "the Tory party you used to vote for". Note the stress Mr Farage placed in his Spectator interview on issues other than an EU referendum – such as grammar schools and wind turbines.

The party gets a bigger vote share in next year's local elections than this year's. Remember, they will be county council polls held in blue rural heartland seats. Mr Farage will thus target disaffected Conservative voters. My guess is he will aim for around 20%.

This paves the way for UKIP to top the polls in the Euro-elections, increasing the pressure on David Cameron for an In-Out poll and encouraging Labour to come out for one to split the Tories – as the possibility of UKIP hitting above 5% in the general election looms.

However, my theme for the day is trying to set out what UKIP's strategy must surely be. It's not a bad one at all for that party. Mr Farage has been around for a long time, is hardened by a hundred battles (external and internal), and will work to see it through.